Method of increasing tensile properties of viscose rayon



Patented Dec. 31, 1935 UNITED STATES BIETHOD OF INCREASING TENSILE PROP- ER-TIES OF VISCQSE RAYON James Willard Humphrey, Claymont, Del., as-

signor to The Viscose Company, Marcus Hook, Pa., a corporation of Pennsylvania No Drawing. Application November 28, 1933, Serial No. 700,148

6 Claims.

The object of my invention is to produce viscose rayon having improved tensile properties.

In carrying out my invention, I add to the viscose solution a hydroxy benzene derivative, preferably an aliphatic derivative of phenol, and then carry out the spinning operation in the usual manner. The resulting yarn has greater tensile strength and extensibility than normal yarn, and also has a marked increase in softness, but no pronounced difierence in dye absorbing capacity or general appearance.

The increase in tensile properties is in proportion to the amount of material added, and can be as high as 35% increase in wet strength, 10% increase in dry strength, and increase in dry extensibility. With larger amounts of material added these strengths may be increased further, but for economical reasons we prefer to add the material in amount of 1% to 2% by 20 weight on the viscose solution, or approximately 15% to 30% on the basis of the cellulose present in the viscose. The major portion of the material so added apparently does not remain with the finished yarn, but is almost entirely lost during the spinning operation.

These materials which I add to the viscose solution to increase the tensile properties of the rayon spun therefrom, are hydroxy benzene derivatives, preferably those in which a hydrogen atom of the benzene ring has been replaced by one or more alkyl or alkyloxy groups. In other words these materials are substituted hydroxy benzenes.

Examples of these materials are: Group I.

Thymol Hydroxy dimethyl Alkyl derivatives of phenol benzene Orthocresol Metacresol Paracresol Group II. Alkyloxy derivatives Resorcinol monoethyl of phenol ether Resorcinol monomethyl ether Group I is preferred, because it is more eiiicient than Group II.

It is not necessary to have the material soluble in the viscose solution. If insoluble, it may be added to the viscose as an emulsion or as the sodium salt which is soluble in the viscose Solution.

As a specific example of the process, viscose solution is prepared as usual, is filtered, aged and then, within twenty-four hours of the proper spinning time, one per cent by weight of metacresol, which is soluble in the viscose, is added. 5 At the proper spinning time and under normal spinning conditions this viscose solution is spun into rayon yarn. The yarn is reeled and processed, etc. Tensile tests made on this yarn show that there is an increase in wet strength of ap- 10 proximately 12 per cent, of dry strength of approximately 6 per cent, and of dry extensibility of approximately 10 per cent over normal viscose yarn similarly spun but without the addition of metacresol to the viscose solution prior to spinl5 ning. The special yarn is approximately 10% softer than normal yarn.

I claim:

1. Method of increasing tensile properties of viscose rayon which comprises adding to the vis- 20 cose solution prior to spinning a substituted hydroxy benzene in which a hydrogen atom of the benzene ring has been replaced by an alkyl group, in amount of 1% to 2% by Weight on the viscose solution, whereby a solution is obtained which 25 upon spinning loses the greater part of the added material, and produces viscose rayon having materially greater tensile properties than viscose rayon similarly spun without the addition and loss of any such material. 30

2. Method of increasing tensile properties of viscose rayon which comprises adding a cresol to the viscose solution prior to spinning, in amount of 1% to 2% by weight on the viscose solution, whereby a solution is obtained which upon spin- 35 ning loses the major portion of said cresol and produces viscose rayon having materially greater tensile properties than viscose rayon similarly spun without the addition of any such material.

3. Method of increasing tensile properties of 40 viscose rayon which comprises adding to the'viscose solution after aging and prior to spinning at least one aliphatic derivative of phenol from the group consisting of thymol, hydroxy dimethyl benzene, orthocresol, metacresol, paracresol, 45 resorcinol monoethyl ether, and resorcinol monomethyl ether, whereby a solution is obtained which upon spinning produces viscose rayon having materially greater tensile properties thain viscose rayon similarly spun without the addi 50 tion of any such material.

4. Method of increasing tensile properties of viscose rayon which comprises adding orthocresol to the viscose solution after aging and prior to spinning, whereby a solution is obtained which 55 upon spinning produces viscose rayon having materially greater tensile properties than viscose rayon similarly spun without the addition of any such material.

5. Method of increasing tensile properties of viscose rayon which comprises adding metacresol to the viscose solution after aging and prior to spinning, whereby a solution is obtained which upon spinning produces viscose rayon having materially greater tensile properties than viscose rayon similarly spun without the addition of any such material.

6. Method of increasing tensile properties of viscose rayon which comprises adding paracresol to the viscose solution after aging and prior to spinning, whereby a solution is obtained which upon spinning produces viscose rayon having materially greater tensile properties than viscose rayon similarly spun without the addition of any such material.

' JAMES WILLARD HUMLPHREY. 

